In the 48 hours since this article went live, we've received a mountain of email from photographers reacting to it. The good news, if you can call it that, is that many EOS-1D Mark III owners are telling us that the article described all too well the autofocus difficulties they're experiencing. We'd heard fewer than 20 complaints about the camera's autofocus before this article was published; since the story went up, that number has climbed past 200. And the email is still rolling in.

Among the comments were questions too; a few of those questions made it clear we needed to say more on a few topics.

Q. First, why is it good news that you've heard from quite a few EOS-1D Mark III shooters citing similar autofocus problems?

Because we're certain that this problem will only get Canon's full attention if they know that a sizeable number of EOS-1D Mark III customers are struggling with its autofocus. And rightly so; it would be foolhardy for Canon to devote a lot of time and energy to a problem that they're only hearing about from a tiny number of people. Canon, like any big company making popular products, needs help in determining what's a major problem - as we think the EOS-1D Mark III's autofocus is - from things that are more minor or even user error.

No. It's critical that Canon have more to go on than either what we've published or the chatter in message boards around the Web. If your EOS-1D Mark III's autofocus is acting up, you need to let them know directly.

Q. You suggested contacting my Canon rep as a way of giving feedback. I don't know who that person is, or even if there is such a person in my area. Is there another way to let Canon know that my EOS-1D Mark III's autofocus isn't working properly?

Yes. Here are some suggestions for the U.S., Canada and Europe:

In the U.S., EOS-1D Mark III owners can fill out an online support ticket, email Canon directly or call:

Online support ticket Click the Support by E-mail link on this page. You'll need to have your camera serial number handy.

Chuck Westfall, Canon USA's Director of Media and Customer Relationship, says any one of these contact methods is a good way to give information about EOS-1D Mark III autofocus problems, information that will be filtered through to the right place.

European Canon Pro Services (CPS) members will find a list of CPS reps and their contact information here. The European online entry page for country-specific tech support is here.

Q. Are you absolutely, positively, 100% sure that the autofocus problems are in all EOS-1D Mark III bodies?

There's no way for us to be absolutely sure of course. And statistically, the number of bodies we've tested vs the number of bodies shipped means we've looked at a pretty small portion of the EOS-1D Mark IIIs out in the world right now. But, the kind and quantity of shooting we've done, combined with a little experience with this stuff and a little common sense too, adds up to the belief here that the problem is in the design of the autofocus system vs there being a few bad EOS-1D Mark III apples around.

If we didn't think that was by far the most likely explanation, we wouldn't have published this story. And the number of photographers we've heard from now that are having the same sorts of troubles in the same types of shooting situations suggests that we're onto something.

But there are other explanations. From where we sit, they fall into the possible-but-not-probable category we wrote about before. If you own the camera or are considering getting one, you'll have to decide which explanation seems most likely to you.

Q. Don't you think Canon should have responded immediately to your article with a statement promising to look into the problem?

While that would have been nice, no, we didn't expect that, at least not in the first day or two after the story's publication. We hope that people at Canon's Tokyo headquarters are already planning a course of action, but the nature of the problem, and the fact that Canon released the EOS-1D Mark III believing that its autofocus was great, means nothing in this process is going to move along as quickly as any of us might like.

Q. It would be good to see some full resolution files that show what you mean by in focus, slightly out of focus and completely out of focus. Can you post some?

The July 2 update on the next page of this article contains links to several downloadable sequences shot with the EOS-1D Mark III.